This disclosure relates to a gas turbine engine, and more particularly, to turbine vane platform cooling arrangements that may be incorporated into a gas turbine engine.
Gas turbine engines typically include a compressor section, a combustor section and a turbine section. During operation, air is pressurized in the compressor section and is mixed with fuel and burned in the combustor section to generate hot combustion gases. The hot combustion gases are communicated through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads.
Both the compressor and turbine sections may include alternating series of rotating blades and stationary vanes that extend into the core flow path of the gas turbine engine. For example, in the turbine section, turbine blades rotate and extract energy from the hot combustion gases that are communicated along the core flow path of the gas turbine engine. The turbine vanes, which generally do not rotate, guide the airflow and prepare it for the next set of blades.
Some turbine vanes may use an impingement plate secured to an airfoil's platform. The platform has an indented region or pocket over which the plate is secured to form a cooling pocket. Impingement plate and platform pocket designs on gas turbine vanes can limit the amount of platform area that is able to be cooled. One example construction has a cast pocket with a raised shoulder around its entire perimeter. Opposing shoulder portions extend from e spaced apart forward and aft rail, reducing the size of the pocket. The impingement plate is welded to this shoulder. One problem is that the material beneath the shoulder and welded plate is uncooled. Moreover, the combination of tolerances from the sheet metal profile and casting profiles requires that the shoulder be oversized to ensure that there is a minimum overlap between the sheet metal and the shoulder.